Elevator load bearing termination assembly

ABSTRACT

A socket device ( 10 ) for securing an end of a load bearing member ( 22 ) includes first socket members ( 26   a  and  26   b ) and second socket members ( 28   a  and  28   b ) that are distinct, separate pieces of material. The second socket members ( 28   a  and  28   b ) are spaced apart from each other at a desired angle and rigidly secured on one side to one of the first socket members ( 26   a ) and on another side to the other first socket member ( 26   b ) to form the socket ( 24 ). A disclosed example includes cooperating tabs ( 38 ) and recesses or openings ( 34 ) for securing the socket members together in a rigidly fixed alignment.

FIELD OF THE INVENTION

This invention generally relates to static connector systems. Moreparticularly, this invention relates to a device for securing an end ofa load bearing arrangement.

DESCRIPTION OF THE RELATED ART

Elevator systems typically include some form of load bearing member,such as roping or a belt for supporting and moving the cab through thehoistway as desired. In some configurations, the belt couples acounterweight to the cab. Regardless of the specific configuration ofthe elevator system, it typically is necessary to secure ends of thebelt to an appropriate structure within the elevator system.

A variety of configurations of assemblies for securing the ends of abelt in an elevator system have been used. One example includes a castsocket and wedge arrangement where a portion of the belt is securedbetween the socket and the wedge. One disadvantage is that the castingprocess is relatively expensive and the integral nature of the castingarrangement limits access to the belt-engaging surfaces within thesocket. This makes it difficult to treat the belt-engaging surfaces,such as by knurling the belt-engaging surfaces, to enhance the grippingcharacteristics. Additionally, it is difficult to achieve tolerancesdesirable for uniform load distribution.

Another example socket is formed from sheet metal and includes two sheetmetal parts bent generally into a U-shape. The U-shaped parts are thenjoined with a dovetail joint and welded along the joint to form thesocket. Shoe parts with knurled belt-engaging surfaces are inserted inthe sheet metal parts. One drawback of this arrangement is a limitedload carrying capacity. It is often difficult to bend sheet metal intothe desired configuration if the sheet metal is over ¼ inch thick.Therefore, it is typically unfeasible to use thicker sheet metal toincrease the load carrying capacity of the socket and larger and morecumbersome shoe parts are required.

Another shortcoming of current arrangements is that the arrangements donot provide the desired dimensional tolerances for many situations. Oneparticular issue is presented by the need to establish and maintain aparallel alignment between opposite sides of the socket and oppositesides of the wedge. Without a truly parallel alignment, the forces onthe load bearing member are not evenly distributed and belt life may becompromised.

There is a need for an improved elevator load bearing terminationarrangement. This invention addresses that need and overcomes theshortcomings described above.

SUMMARY OF THE INVENTION

One example socket for securing an end of an elongated load bearingmember in an elevator system includes at least one first socket memberthat at least partially forms the socket. Second socket members that areseparate and distinct from each other and from the first socket memberare spaced apart from each other for receiving a load-bearing member.Each second socket member is rigidly fixed to the at least one firstsocket member.

One example method of making a socket for use in an elevator system usesa first socket member and second socket members that are separate,distinct pieces. The method includes inserting a plurality of tabs thatextend either the first socket member or the second socket members intoa corresponding plurality of recesses in the other of the first socketmember or the second socket members. This rigidly secures the firstsocket member and the second socket members together.

The various features and advantages of this invention will becomeapparent to those skilled in the art from the following detaileddescription of a currently preferred embodiment. The drawings thataccompany the detailed description can be briefly described as follows.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a perspective view of an example socket device.

FIG. 2 illustrates a view of the socket device along the section line2-2 shown in FIG. 1.

FIG. 3 illustrates a view of selected portions of the socket device ofFIG. 1.

FIG. 4 illustrates locking between side plates and keeper parts of thesocket device of FIG. 1 along the section line 4-4 shown in FIG. 1.

FIG. 5 shows a modified example of locking the keeper parts and sideplates together with a fastener.

FIG. 6 shows a modified example of locking the keeper parts and sideplates together with a bolt.

FIG. 7 schematically shows an example positioning member used toprecisely assemble a socket device.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIGS. 1 through 3 illustrate a device 10 for handling an end of a loadbearing member 22 in an elevator system. The load bearing member 22 inthe illustrated example is a flat belt, however, any load bearing memberwithin an elevator system that can be accommodated using a socket andwedge arrangement designed according to this invention may be used. Theterm “belt” as used in this description should not be construed in itsstrictest sense. It should be considered synonymous with roping or loadbearing member.

In the illustrated example, a socket 24 includes side plates 26 a and 26b (i.e., first socket members) and keeper parts 28 a and 28 b (i.e.,second socket members) between the side plates 26 a and 26 b. The keeperparts 28 a and 28 b and the side plates 26 a and 26 b are distinct,separate pieces that are rigidly secured together and cooperate with awedge 30 to secure the end of the load bearing member 22 in a desiredposition. The example device 10 has advantages in simplifying themanufacture and assembly of the socket 24 and allowing scaling of thedesign to a variety of load requirements. Additionally, the exampledevice 10 facilitates flatness, parallelism, and dimensional control,which eliminates the need for insert shoe parts.

As can be appreciated from one or more of the drawings, the device 10includes relatively few parts, including the side plates 26 a and 26 b,the keeper parts 28 a and 28 b, the wedge 30, and a connector portion 32that are assembled together to form the socket 24.

In the illustrated example, the side plates 26 a and 26 b each includerecesses 34 such as slots for assembling the socket 24. In this example,the recesses 34 comprise openings through each side plate 26. Each ofthe keeper parts 28 a and 28 b includes tabs 38 with beveled endportions that are received at least partially into a correspondingrecess 34. In the illustrated example, the tabs 38 include a generallyrectangular cross-sectional profile. Given this description, one ofordinary skill in the art will recognize suitable profiles other thanrectangular to meet their particular needs.

The side plates 26 a and 26 b also each include a connector opening 36for receiving the connector portion 32. In the illustrated example, theconnector portion 32 includes a bridge member 44 having an internallythreaded opening 33 that receives a rod 35 that secures the device 10 toa support in a known manner. In some examples, a pin P (FIG. 2) is usedto secure the rod 35 and bridge member 44 together.

In one example, the recesses 34, connector openings 36, tabs 38, andshape of the side plates 26 a and 26 b and keeper parts 28 a and 28 bare laser cut from a metal block. Given this description, one ofordinary skill in the art will recognize alternative processes andmaterials for making the socket 24.

In the illustrated example, the side plates 26 a and 26 b are spaced auniform distance apart (i.e., are parallel), and the keeper parts 28 aand 28 b are transverse to each other and generally perpendicular to theside plates 26 a and 26 b. The terms “parallel” and “perpendicular” asused in this description refer to the nominal relative positioningbetween the parts and are not intended to be restrictive in a strictgeometrical sense.

In the illustrated example, some of the recesses 34 are aligned along afirst plane P₁ and other recesses 34 are aligned along a second plane P₂with a desired oblique angle α such as 15° between them. In thisexample, the angle α corresponds to the position of the keeper parts 28a and 28 b relative to one another.

FIG. 4 illustrates a view along the section line shown in FIG. 1 andshows a locking connection between the tabs 38 of the keeper part 28 band the recesses 34 of the side plates 26 a and 26 b. The lockingconnection for the keeper part 28 a is similar. The locking connectionprovides the benefit of maintaining the keeper parts 28 a and 28 b atthe desired angle while uniformly distributing shear loads from thekeeper parts 28 a and 28 b to the side plates 26 a and 26 b. In thedisclosed example, using a plurality of tabs also provides multiplelocations for load distribution.

In this example, the beveled end portions of the tabs 38 form channels40 with the recesses 34. In one example, the channels 40 receive afiller material 42 (e.g., braze, solder, or weld filler material) tosecure the keeper parts 28 a and 28 b together with the side plates 26 aand 26 b. Although the illustrated example shows the beveled endportions of the tabs 38 being flush with the side plates 26 a and 26 b,in some examples the tabs 38 extend completely through the recesses 34or only partially into the recesses 34.

Likewise, the connector portion 32 includes a bridge member 44 havingbeveled ends 46 that are received into the respective connector openings36. This provides a locking connection similar the locking connectionbetween the tabs 38 and the recesses 34. The bridge member 44 transfersload from the side plates 28 a and 28 b to the rod 35. Given thisdescription, one of ordinary skill in the art will recognize suitablebridge member 44 shapes and configurations other than what is shown tomeet their particular needs.

In one example, one or more the surfaces of the wedge 30 and keeperparts 28 a and 28 b are treated to enhance the gripping characteristicsof the socket 24. In one example, contact surfaces 50 of the keeperparts 28 a and 28 b and wedge 30 are milled, knurled, or grooved in aknown manner to increase friction with the load bearing member 22. Theseparate, distinct keeper parts 28 a and 28 b provide the benefit ofbeing easily accessible for treatment before assembly with the sideplates 26 a and 26 b.

As can be appreciated from the drawings and description, the designedsize of the side plates 26 a and 26 b and keeper parts 28 a and 28 b canbe scaled up or down to accommodate a variety of desired load bearingcapacities. Since the side plates 26 a and 26 b and keeper parts 28 aand 28 b are formed or cut from metal blocks instead of bent sheet metalas in some prior designs, there are fewer manufacturing limitations thatinhibit scale up compared to previously known arrangements.Additionally, this facilitates flatness, parallelism, and dimensionalcontrol.

In another example, the angle α and a wedge angle ω (FIG. 2) areunequal. In one example, the wedge angle ω is greater than the angle α.In a further example, the wedge angle ω is ½° greater than the angle α.

This provides the advantage of increasing the breaking strength of theload bearing member 22. In some prior arrangements, breaking of the loadbearing member occurs at the entrance of the socket. At this point,tensile stress from the load is a maximum. The stress in the loadbearing member is a combination of the tensile stress and orthogonalcompressive stress from wedging force. As a result, with evenlydistributed wedging pressure, von Mises stress at the entrance of thesocket is a maximum. By selecting the right geometry of wedge/socketsurfaces, the pressure is redistributed in such a way that maximumpressure will be inside of the socket where tensile stress is lower.That will increase the breaking force of the load bearing member.

FIG. 5 illustrates a modified example. In this example, a fastener 54extends through each of the recesses 34 of the side plates 26 a and 26 bwith corresponding openings 56 in the keeper parts 28 a and 28 b tosecure the device 10 together. In one example, the fastener 54 andopenings 56 are threaded to facilitate assembly.

FIG. 6 illustrates another modified example, wherein the fasteners 54are bolts that extend entirely through the keeper parts 28 a and 28 band extend from each side of the side plates 26 a and 26 b. The boltsare secured in place using a nut 58. Given this description, one ofordinary skill will recognize other ways of securing the parts togetherto meet their particular needs.

In one example, to facilitate precise assembly of the device 10, apositioning member 52 as shown in FIG. 7 is used to precisely align theside plates 26 a and 26 b and keeper parts 28 a and 28 b. In theillustrated example, the positioning member 52 is approximately the samecombined size and shape as a corresponding wedge 30 (shown in phantom)and load bearing member 22 that will be used with that particular socket24. The thickness T of the load bearing member 22 is included on thedimensions of the positioning member 52 in this example.

To assemble the device 10, the tabs 38 of the keeper parts 28 a and 28 bare fit into the recesses 34 of the side plates 26 a and 26 b. In oneexample, there is some play between the tabs 38 and openings 36. Thepositioning member 52 is then inserted into the socket 24 between thekeeper parts 28 a and 28 b and side plates 26 a and 26 b. A positioningmember in the shape of the bridge member 44 is also used for aligningthe tops of the side plates 28 a and 28 b. The keeper parts 28 a and 28b, side plates 26 a and 26 b, and positioning member 52 are then clampedtogether and the distinct pieces are welded, brazed, or soldered (forexample) to secure the parts together before removing the positioningmember 52. The positioning member 52 maintains a precise alignmentbetween the side plates 26 a and 26 b and keeper parts 28 a and 28 bduring the welding, brazing, or soldering process. This feature providesthe benefit of establishing a precise socket 24 assembly, which isdesired for maintaining a wedge in a desired position and achievinguniform load distribution on a load bearing member.

The preceding description is exemplary rather than limiting in nature.Variations and modifications to the disclosed embodiment may becomeapparent to those skilled in the art that do not necessarily depart fromthe essence of this invention. The scope of legal protection given tothis invention can only be determined by studying the following claims.

1. A socket for securing an end of an elongated load bearing membercomprising: two first socket members each comprising a separate anddistinct piece that at least partially form a socket; and two secondsocket members each comprising a separate and distinct piece, the secondsocket members are spaced apart from each other for receiving aload-bearing member between the second socket members, and each secondsocket member is rigidly fixed to at least one of the two first socketmembers.
 2. The socket device as recited in claim 1, wherein each of thetwo first socket members are rigidly fixed to each of the two secondsocket members.
 3. The socket device as recited in claim 2, wherein thetwo first socket members are parallel to each other.
 4. The socketdevice as recited in claim 1, wherein the two second socket members areperpendicular to the at least one of the two first socket members. 5.The socket device as recited in claim 1, wherein the two first socketmembers each comprise a locking feature and the two second socketmembers each comprise a corresponding locking feature to secure the twosecond socket members to the two first socket members.
 6. The socketdevice as recited in claim 5, wherein the locking feature comprises atleast one recess that extends at least partially into each of the twofirst socket members and the corresponding locking features comprise atleast one tab that extends from each of the two second socket membersand is received at least partially within the recesses.
 7. The socketdevice as recited in claim 6, wherein the recesses of at least one ofthe two first socket members comprise first openings arranged along afirst plane and second openings arranged along a second plane and thatis transverse to the first axis.
 8. The socket device as recited inclaim 7, wherein the first plane and the second plane form an angle ofabout 15°.
 9. The socket device as recited in claim 7, comprising awedge for insertion between the second socket members, the wedge havingan associated wedge angle that is different from an angle between thefirst plane and the second plane
 10. The socket device as recited inclaim 9, wherein the wedge angle is greater than the angle between thefirst plane and the second plane.
 11. The socket device as recited inclaim 10, wherein the wedge angle is ½° greater than the angle betweenthe first plane and the second plane.
 12. The socket device as recitedin claim 6, wherein the recesses each include an opening having aperipheral surface and the tabs include beveled ends that form channelswith the peripheral surfaces.
 13. The socket device as recited in claim12, comprising a welded connection at the channels.
 14. The socketdevice as recited in claim 6, wherein at least one of the tabs comprisea rectangular protrusion.
 15. The socket device as recited in claim 1,wherein the two first socket members include a connector opening thatreceives at least a portion of a connector member for connecting thesocket to a support.
 16. The socket device as recited in claim 15,wherein the connector opening includes a peripheral surface and theconnector member includes a beveled end that forms a channel with theperipheral surface.
 17. The socket device as recited in claim 1,comprising fasteners that secure the first socket members and the secondsocket members together.
 18. The socket device as recited in claim 17,wherein the fasteners extend at least partially into one of the twosecond socket members.
 19. The socket device as recited in claim 18,wherein the fasteners extend entirely through the one of the two secondsocket members.
 20. A method of making a socket for use in an elevatorsystem using two first socket members that at least partially form thesocket, and two second socket members, wherein the first socket membersand second socket members are all separate, distinct pieces, comprising:rigidly fixing each of the two second socket members to each of the twofirst socket members to at least partially form a socket between the twosecond socket members.
 21. The method as recited in claim 20, includinginserting a plurality of tabs that extend from the two first socketmembers or the two second socket members into a corresponding pluralityof recesses in the other of the two first socket members or the twosecond socket members to rigidly secure the two first socket members andthe two second socket members together.
 22. The method as recited inclaim 21, including welding together the plurality of tabs and thecorresponding plurality of recesses.
 23. The method as recited in claim21, including inserting a positioning member between the second socketmembers to achieve a spacing between the second socket members that isequal to a combined size of a wedge and a load-bearing member.
 24. Themethod as recited in claim 23, comprising achieving a desired alignmentof the second socket members corresponding to a configuration of thepositioning member.
 25. The method as recited in claim 23, includingclamping the positioning member between the second socket members. 26.The method as recited in claim 21, including inserting first tabs of theplurality of tabs that extend from each of the two second lockingmembers into first recesses of the plurality of recesses within the twofirst socket members.
 27. The method as recited in claim 20, includingrigidly fixing the two second socket members at an angle relative toeach other and perpendicular to the two first socket members.
 28. Asocket made by the method recited in claim 20, wherein the two firstsocket members and the two second socket members comprise at least fourdistinct, separate pieces, the two second socket members are spacedapart from each other for receiving a load-bearing member between thetwo second socket members, and each of the two second socket members isrigidly fixed to each of the two first socket members.